This invention relates generally to mufflers and more particularly to sound attenuating exhaust mufflers for internal combustion engines.
Sound attenuating mufflers exist in the art, and as such their structure and function are well known. U.S. Pat. No. 4,574,914, U.S. Pat. No. 6,089,347, U.S. Pat. No. 6,286,623 and U.S. Pat. No. 6,341,664 disclose various muffler designs, the entire contents of which are incorporated herein by reference in their entireties.
While it is important for a muffler to attenuate engine noise, it is also desirable for a muffler to have sonic characteristics that are pleasing to the ear throughout the engine speed range. Desirable acoustics can range from a low RPM rumble to a crisp and aggressive high RPM exhaust note.
Muffler design also affects engine power output. A muffler preferably allows for a high exhaust flow rate.
There remains a need for novel muffler designs capable of producing desirable sound characteristics throughout the engine speed range while also providing sufficient noise attenuation and allowing sufficient flow and power characteristics. There remains a need for muffler designs that allow for a high flow rate with minimal drone at cruising speeds. There also remains a need for muffler designs having said functional characteristics that are less labor intensive and less expensive to manufacture than traditional designs.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.